Transaction duration metrics not published for apm-server

[dgieselaar]

When aggregation of transaction duration metrics is enabled (via apm-server.aggregation.enabled=true), metrics for apm-server are seemingly not published. For other services, transaction duration metrics are published.

[axw]

apm-server/beater/beater.go

Line 157 in fa9bc09

return tracerServer.serve(args.Reporter)

The trace server is running with the core reporter, and not the wrapped one (i.e. the one that performs aggregation.) We'll probably need to change CreatorParams.RunServer to be a middleware type of function, which takes a RunServerFunc and returns a wrapped RunServerFunc.